Heater for liqtjid-he at -transmission systems



Sept. 18, 1928. S 1,684,963

D. M. LUEHRS HEATER FOR LIQUID HEAT TRANSMISSION SYSTEMS Filed Oct. 6, 1924 2 Sheets-Sheet 1 Sept. 18, 1928. 1,684,963

D. M. LUEHRS HEATER FOR LIQUID HEAT TRANSMISSION SYSTEMS Filed Oct. 1924 2 Sheets-Sheet 2 Patented Sept. 18, 1928.

- 7 UNITED STATES 1,684,963 PATENT OFFICE.

DANIEL M. LUEHRS, F CLEVELAND, 01110.

HEATER 'FOR' LIQUID-HEAT-TRANSMISSION- SYSTEMS,

Application filed October 6,1924. SerialNq. 742017.

In systems of heat distributionin which high flash mineral oil isheatcd to a high temperature and pumped through distributing apparatus in which the heat is utilized,

various kinds of heaters have been employed One of these is in the form of a water tube boiler, with suitable headers, and the heat is applied to the tubes inthe usual way by burnersor al'ire enclosed in a fireplace, be-

neath the tubes, Vith this type of boiler, oil within the tubes, and more particularly in the lowermost tubes, is often carbonized by the application of too great heatto the tubes. i

The present invention relates to means for heating the oilin. such tubular heaters electrically. In carrying out the invention, I provide electric heating units in the form of rods which are inserted through hand holes in the headers into the tubes and which are supported centrallyv in the tubes by plugs which are removably secured in the hand holes. The unitsn iaybe connected to the current source in any desired way and the heat may be applied so as to raise the 'temperature of the oil to any desired degree withoutda-nger of causing it to be carbonized in the tubes.

tion isthat I am enabled to convert heaters of the water-tube type which have been eonstructed for use With fires or fuel burners, into electrical heaters by simply removing the usual hand holecovers and replacing them with plugs in which are supported the heating units. 7 i

In the z-iccoi'npanying drawing,

Fig. 1 is a side elevation, partly in section, of, a heater embo dvin m in13rore-- ments;

Fig. 2 is a top plan view of the same; Fig. 3 is a side elevation, partlyin section, of a different form of tubular heater, equipped with electrical heating units; and, Fig. 4 is a top plan view of the same. Referring to Figs 1 and 2, oil"; the drawing g (1 represents a tubular boiler comprising.

headers 1. and 2 connected by tubes 3, which are upwardly inclined from the header 2 to the header 1. There may be any desired in the ordinary water tube boiler, in vertical and horizontal rows.

tube is connected to and communicates with the interiors of both headers. Theoil which is to be heated enters the lower part ofthe One advantage of the inven-' 7 ably controlled.

number of tubes, and these are arranged, as

The headers ex tend the full height of the heater and each the distributing system by a suitable pump,

not shown in the drawing. In order to heat the oil as it passes through the heater, I dispense with the usual hand hole covers on the headers and substitute closures in the form of plugs 6, which are threaded into the hand hole openings 7, and these plugs have'central openings in which are secured heating elements or units 8, in the form of rods, which units are secured within the plugs and extend through the headers and into the tubes. The heating units are considerably smaller in diameter than the internal diameters of the tubes and are supported axially in the tubes by the plugs. As shown in the drawing, two heating units extend into each tube through the opposite headers. The terminals 9 and 10, leading from each heating unit, which are accessible from without the headers, may be connected in any desired manner, through a suitable panelboard to the current source, and the flow of current through the heaters will be suitably controlled to heat the oil to the desired temperature. It will be evident that if a heating unit becomes burned out or otherwise damaged, it may be readily replaced by another. Thc'oil entering at the pipe 4. will flow through the headers and tubes in contact with the heating units and will become heated and then flow out through the distributing pipe 5. The temperature of the oil leaving the heater will,

of course. depend upon the rate of flow through the heater and the tci'nperature of the heating unit. both of which will be suit- In Figs. 3 and a, I have shown a modified form of heater. equipped with the same'form oi. heating units as in the previously described figures. In Figs. 3 and hthe heater 6 is constructed with two setsof superposed headers, extending transversely of the heater, and the tubes extending from the bottom to the top of the heater are connected in series through these headers. Thus, at one end of the heater is a set of headers 1.1, 12, 1.3 and 14.. arranged one above the other, and at the opposite end of the heater is a set of head ers 15, 1.6 and 17, similarly arranged. headers 11 and 15 are connected by a trans- The verse row of tubes 18, and the headers 15 and 12 are connected by a similar row of tubes 19; the headers 12 and 16 are connected by a row of tubes 20; the headers 16 and 13 are connected by a row of tubes 21; the headers 13 and 17 are connected by a row of tubes 22, and the headers 17 and 1 1 are connected by a row of tubes 23. An inlet pipe 1 is connected to the header 11, and an outlet pipe 5 is connected to the header 14. The heating units 8 are supported in the tubes by plugs 6, as in the previously described figures.

It will be understood that when the fluid is pumped through the heater shown in the Figs. 3 and l, it will flow through the header 11 into the tubes 18, thence through header 15 to the tubes 19, and thence successively through header 12 to the tubes 20, header 1.6. tubes 21. header 13. tubes header 1'7. tubes 23 and header it to the outlet pipe 5. In passing through the several headers and pipes, the oil will flow in direct contact with the heating units. In this form of heater, all of the oil necessarily flows in direct contact with heating units during practically its entire circuit through the heater since the tubes extending from the bottom to the top of the heater are connected in series through the headers and the heating elements extend into all of the tubes and through the headers. The temperature to which the oil is heated will. of course,depend upon the rate of flow of the oil through the heater and the current supplied to the heating elements.

lVhat I claim is:

1. An oil heater comprising two opposing sets of superposed headers, tubes extending between and communicating with the interiors of the opposing headers, hand holes in the opposing headers in line with the tubes, plugs fitting in the hand holes and electric heating rods projecting into the tubes from their opposite ends, each rod supported in one of the plugs and extending through a header and part way, only, through a tube, said rods being spaced from the inner walls of the tubes.

2. An oil heater comprising two opposing sets oi superposed headers, tubes extending between and communicating with the interiors of the ep iiosing headers and connected in series thereby From the bottom to the top of the heater, hand holes in the OI'JDOSlDg headers in line with the tubes, plugs fitting in the hand holes and electric heating rods projecting into the tubes from their opposite ends, each rod supported in one of the plugs and extending through a header and part ay. only, through a tube, said rods being spaced from the inner walls of the tubes.

In testii'nony whereof I hereunto aflix my signature.

DANIEL M. LUEHRS. 

